you can go to any auto parts store and get some gasket material, then take a piece of it and lay it against your valve cover and start to press around the edge of the cover. this will give you an impression on the material. then just cut that out, that will be the out side edge of your gasket. to get the inside, you can eyeball it and trim to fit. or you can measure the lip on the valve cover, and transfer that to the material and mark all the way around. then cut the center out. i'm sure other people do it differently, but that's what works for me. hope this helps you out